(Phys.org)—Scientists from Taiwan have made interlocking daisy-chain-like molecular structures that can switch from an expanded and contracted position based on the removal and addition of zinc, mimicking muscle behavior. ...

(Phys.org)—Russian astronomers have recently observed a giant radio flare from a strong X-ray binary source known as Cygnus X-3 (Cyg X-3 for short). The flare occurred after more than five years of quiescence of this source. ...

The living machinery responsible for photosynthesis - while commonplace and essential to life on Earth - is still not fully understood. One of its molecular mysteries involves how a protein complex, photosystem II, harvests ...

(Phys.org)—A new accreting millisecond X-ray pulsar (AMXP) has been found in one of our galaxy's most massive clusters, NGC 2808. The newly detected AMXP received designation MAXI J0911-655 and is part of an ultra-compact ...

Scientists have used the powerful X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory to make the first snapshots of a chemical interaction between two biomolecules - one that flips an RNA "switch" ...

This image shows the location of a remarkable source that dramatically flares in X-rays unlike any ever seen. Along with another similar source found in a different galaxy, these objects may represent an entirely new phenomenon, ...

(Phys.org)—NASA's Chandra X-ray Observatory has helped astronomers to uncover a previously unidentified X-ray point source at the massive black hole in the center of a distant compact starburst galaxy known as Henize 2-10. ...

(Phys.org)—A team of astronomers led by Enrico Bozzo of the University of Geneva, Switzerland, has recently studied a prototype of a supergiant fast x-ray transient (SFXT), designated IGR J17544-2619. The researchers investigated ...

(Phys.org)—Canadian astronomers report the discovery of a previously unseen infrared source in supernova remnant RCW 103, located some 10,000 light years away. According to a paper published Oct. 7 on arXiv.org, this newly ...

(Phys.org)—A team of researchers led by Andrea Maselli of the Institute of Space Astrophysics and Cosmic Physics of Palermo, Italy, has conducted an observational campaign of a group of unassociated radio sources with NASA's ...

X-ray

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays. In many languages, X-radiation is called Röntgen radiation after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had called them X-rays to signify an unknown type of radiation.:1-2

X-rays are primarily used for diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. X-rays are a form of ionizing radiation and as such can be dangerous.

X-rays from about 0.12 to 12 keV are classified as soft X-rays, and from about 12 to 120 keV as hard X-rays, due to their penetrating abilities.

The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). So older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually defined by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.